In 3GPP (3rd Generation Partnership Project), which is a project aiming to standardize a mobile communication system, a discontinuous reception (DRX) is prescribed as an intermittent reception technique to reduce power consumption of a radio terminal. The radio terminal executing a DRX operation intermittently monitors a downlink control channel. A cycle in which the downlink control channel is monitored is referred to as “DRX cycle”.
In recent years, machine-type communication (MTC) in which a radio terminal performs communication without human intervention in a mobile communication system has attracted attention. From such a background, an ongoing discussion is a new introduction of an extended DRX cycle longer than a conventional DRX cycle to further reduce power consumption (for example, see Non Patent Document 1). The DRX using the extended DRX cycle is referred to as “extended DRX”.